This invention relates in general to a method and apparatus for processing network calls within a telephone switching system and in particular to a time of day dependent method and apparatus for restricting access to a particular telephone number.
Telephone systems have become increasingly sophisticated and are designed to provide many services to subscribers. A typical telephone network 10 is schematically illustrated in FIG. 1 where the arrows indicate the flow of information within the network. An individual subscriber telephone 12 is connected to a Local Exchange Carrier (LEC) switch 14. While one telephone 12 is shown in FIG. 1, it will be appreciated that a plurality of telephones and/or other devices, such as personal computers also may be connected from the subscriber to the LEC switch 14. The LEC switch 14 is part of a local telephone company and provides a gateway for connection to long distance carriers, wireless networks and other local telephone companies which are collectively shown in FIG. 1 as a Public Switched Telephone Network (PSTN) 16. The LEC switch 14, which is commonly referred to as a Service Switching Point (SSP) is also connected through a Signaling Transfer Point (STP) 17 to a Service Control Point (SCP) 18. The STP 17 functions as a signal router while the SCP 18 includes a data base and operating instructions for the LEC switch 14. As shown by the double headed arrows in FIG. 1, information flows in both directions between the individual components. Also, note that the connection between the LEC switch 14, or SSP, and the SCP 18 is indicated by a dashed line. The dashed line represents a signaling path between the LEC switch 14 and the SCP 18. There is not a voice bearing path connecting the LEC switch 14 and the SCP 18. Instead, logic contained in the SPC 18 responds to signals sent from the LEC switch 14 with instructions concerning how the LEC switch 14 should respond to incoming calls.
The LEC switch 14 recognizes service requests from either the subscriber telephone 12 or the PSTN 16. Upon receiving an incoming call from the PSTN 16 for the telephone 12, the LEC switch 14 will attempt to route the call to the telephone 12. If the LEC switch 14 is not able to complete the call, the LEC switch 14 will send a query to the SCP 18 that includes the Automatic Number Identification (ANI) of the called and calling telephone station. The SCP 18 will access its data base, and, based upon the information stored therein, retrieve a set of instructions that are forwarded to the LEC switch 14 for handling the call. For example, if the telephone 12 is busy, the SCP 18 can cause the LEC switch 14 to send a “call waiting” signal to the telephone 12.
The SCP 18 can include a Service Management System (SMS) 19 that provides instructions to the SCP 18 concerning the handling of calls. The combination of the SCP 18 and SMS 19 is referred to as an Advanced Intelligent Network (AIN) 19A. For example, the subscriber can instruct the SMS 18 to forward all incoming calls to another telephone ANI. The SMS 18 will store the alternate ANI and transmit the alternate number to the SCP 18. The SMS 18 will also activate an AIN feature in the LEC switch 14 to forward incoming calls to the subscriber ANI to the SCP 18 for rerouting to the alternate ANI. Accordingly, incoming calls to the subscribers' telephone 12 will be intercepted by the LEC switch 14 and forwarded to the alternate ANI, as per instructions received from the Service Control Point 18.
The AIN 19A can also provide a number of selective services to the individual telephone subscriber. Such services include a “call prompter” service with which the AIN 19A provides a request that the caller enter a series of digits via a Dual Tone Multi-Frequency (DTMF) telephone keypad. The digits are used by the AIN 19A to direct routing of the call or to provide a security check. Additionally, the AIN 19A can provide an “inbound call restriction” service that filters the incoming calls by area code, exchange code (NNX) or ANI. The inbound call restriction service also may be selectively operative during designated time of day or day of week. Another option is a “do not disturb” service which provides call filtering that allows access only to calls from preselected ANI's.
Unfortunately, with the increasing sophistication of telephone systems, the number of undesirable telephone calls is increasing. For example, dinner time is a favorite time for telemarketers to attempt to contact potential customers. As described above, the AIN network illustrated in FIG. 1 can be utilized to block all calls to a designated telephone ANI during predetermined time periods. However, there are certain calls that a subscriber might want to receive regardless of the time of day, such as calls from a child who is attending a distant college. Accordingly, it would be desirable to provide a telephone system that could screen incoming calls and only block some of the calls while allowing selected calls to be completed. It would also be desirable to sort the blocked calls for a later response.